Ahstract-In this paper we study the effect of Hole Transport Layer NPB (N,N'-diphenyl-N,N'-his(l-naphtyl)-J,J '-hiphenyl-4,4" diamine) and Electron Transport Layer on the performance of a single layer of Blue Organic Light Emitting Diode. Three different structures are analyzed and are compared to the reference structure. SimOLED is used to simulate and to analyze both electrical and optical characteristics. We found that the addition of 1 nm hole transport layer significantly improve the luminance by more than 1.5 times which is ascribed to the increase of the hole injection leading to the balance charge in the emissive layer. On the other hand, the application of 1 nm electron transport layer provide lower operating voltage which become more significant when both hole transport layer and electron transport layer are combined. The proposed structure reaches a luminance of 49,543 cd/m 2 at 10 V.